Only 1 in 10,000 people have absolute or "perfect" pitch, the ability to hear a tone and tell what note it is. This unusual ability is acquired early in life, typically learned during training at about four to six years of age, and there are no records of adults acquiring the ability. But a new study shows that people who took a drug normally used as a mood-stabilizer became significantly better at identifying the pitch of sounds, after two weeks of training, compared to those who took a placebo. 

The drug, known as valproic acid or Valproate, "restores the plasticity of the brain to a juvenile state," Harvard researcher and study co-author Takao Hensch told NPR. It's the first time that a drug has ever been shown to help people become better at identifying pitch, he said. The study was conducted on 24 young men with little musical training, half of whom took the drug and half of whom took a placebo.